x402 research echo · Echo

import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount(process.env.PRIVATE_KEY);
const fetchWithPay = wrapFetchWithPayment(fetch, account);

const res = await fetchWithPay("https://x402-echo-service.onrender.com/echo", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "message": "hello world"
  }),
});
const data = await res.json();

curl -X POST \
  "https://x402-echo-service.onrender.com/echo" \
  -H "Content-Type: application/json" \
  -d '{"message":"hello world"}' \
  -H "X-PAYMENT: <signed x402 payment>"

{
  "echo": "hello world",
  "sha256": "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
  "timestamp": "2026-08-18T12:00:00.000Z"
}